5.7. Phrase Markup

5.7. Phrase Markup

Phrases may be marked up according to idiomatic usage, typographic
appearance, or for use as hyperlink anchors.

User agents must render highlighted phrases distinctly from plain
text. Additionally, <EM> content must be rendered as distinct from
<STRONG> content, and <B> content must rendered as distinct from <I>
content.

Phrase elements may be nested within the content of other phrase
elements; however, HTML user agents may render nested phrase elements
indistinctly from non-nested elements:

plain <B>bold <I>italic</I></B> may be rendered
the same as plain <B>bold </B><I>italic</I>